Tuesday, September 29, 2015

Researchers from the
University of Missouri School of Medicine have found that when a person
sits for six straight hours, vascular function is impaired -- but by
walking for just 10 minutes after a prolonged period of sitting,
vascular health can be restored.

"It's easy for all of us to be consumed by work and lose track of
time, subjecting ourselves to prolonged periods of inactivity," said
Jaume Padilla, Ph.D., an assistant professor of nutrition and exercise
physiology at the MU School of Medicine and lead author of the study.
"However, our study found that when you sit for six straight hours, or
the majority of an eight-hour work day, blood flow to your legs is
greatly reduced. We also found that just 10 minutes of walking after
sitting for an extended time reversed the detrimental consequences."

During the study, the researchers compared the vascular function of
11 healthy young men before and after a period of prolonged sitting. The
findings indicated that blood flow in the popliteal -- an artery in the
lower leg -- was greatly reduced after sitting at a desk for six hours.
Researchers then had the participants take a short walk, and found that
10 minutes of self-paced walking could restore the impaired vascular
function and improve blood flow.

"When you have decreased blood flow, the friction of the flowing
blood on the artery wall, called shear stress, is also reduced," Padilla
said. "Moderate levels of shear stress are good for arterial health,
whereas low levels of shear stress appear to be detrimental and reduce
the ability of the artery to dilate. Dilation is a sign of vascular
health. The more the artery can dilate and respond to stimuli, the
healthier it is."

Many workplaces are sedentary environments, and the researchers said
it's important that people understand the effects of sitting on their
vascular health. By breaking up desk time with a short walk, workers can
offset the harm caused to vascular blood vessels.

"Studies have shown that sitting less can lead to better metabolic
and cardiovascular health," Padilla said. "However, more research is
needed to determine if repeated periods of reduced vascular function
with prolonged sitting lead to long-term vascular complications."